Platform-scale



- 3 Sheets-Sheet 1. -T. FAIRBANKS.

Platform Scales.

No. 26,484. Patented Dec. 20, 1859:

GRovNmPLAN" l 3 Sheets-Sheet 2.

T. FAIRBANKS.

Platform Scales.

PatentedY Dec, 20. 1859.

. 3 Sheets-Sheet 3. T. FAIRBANKS.

, Platform Scaies.

No. 26,484. Patented Dec. 2o, 1859.

#27H65 ses muy '2f/WM? .Mm /f/Wfw THADDEUS FAIRBANKS, OF

ST. JOHNSBURY, VERMONT.

PLATFORM-SCALE.

Specification of Letters Patent No.

To all whom it may concern.'

Be it known that I, THADDEUS FAIRBANKS, of St. Johnsbury, in the countyof Caledonia and State of Vermont, have invented an Improvement inPlatform- Scales for IVeighing Heavy Bodies; and I do hereby declarethat the same is fully described and represented in the followingspecification and the accompanying drawings, of which- Figure l, denotesa ground plan of the framing of a platform and pit frame of a scale orweighing machine, the said figure exhibiting (by links, A, B, C and D)the general arrangement of the weighing levers by which the platform issupported. Fig. 2, is a side elevation of the platform. Fig. 3, asectional view of the platform and its pit frame. Fig. 4, anothersectional view, exhibiting the relative situations of the three leversA, B, C, and their knife edge bearings. Fig. 5, is a diagramillustrating the arrangement of the devices for supporting the lappedends of the levers, A and B, and connecting them with the steelyard rod,Fig. 6, is a top view of the bottom bar of what is termed the yoke,while Fig. 7, is an underside view of the top bar of said yoke. Fig. 8,is an end view of the yoke and ex hibits in dotted lines the bearingsand the bearing pivots of the lapping levers.

The nature of my invention consists principally, in a peculiarapplication and arrangement of a yoke, stirrup, pivots and bearings,whereby the lapped ends of the two multiplying and transmitting levers,A, and B, are supported and connected with the depending rod of thesteelyard.

In the drawings, E, represents the plat-- form on which the article tobe weighed is to be supported, F, being the surrounding or pit frame towhich the levers, A, B, C, D, are suspended in the usual manner. The twolevers, A, B, near their outer ends cross one another, one being made toproject over the other as shown in Fig. 4t, wherein the lever, B, or apart thereof is represented as extending underneath the lever, A, thesame also being exhibited in Figs. 5 and 8. At or near the end of thelever, A, two conical pivots, a, Z), are made to extend vertically inopposite directions from the said lever; while from the end of thelever, B, and in a vertical line with the pivots, a, o, another conicalpivot, c, projects downward, the same being as shown in Figs. 4 and 5.The two levers, A, and B, extend into a yoke, G, which consists of arectangular frame, whose upper and lower bars, d, e, at the centers oftheir 26,484, dated December 20, 1859.

inner surfaces are furnished with concave bearings or steps, f, g, forthereception of the pivots, a, and c. Furthermore, the rod, I, thatextends downward from the steelyard is furnished at its lower end with astirrup, whose foot or crossbar, z., is placed within the yoke, G, whileits rods or prongs, z', z', pass upward through openings, 7c, lo, madethrough the bar, cl, of the yoke, these openings being large enough toallow the yoke to play freely without contact with the stirrup.Furthermore, the lower bar, It, of the stirrup is constructed with ahollow step or bearing, Z, for the reception of the pivot, b, whichextends downward from the lever, A.

From the above, it will be seen that the yoke is not only supported bythe pivot of the lever, A, but such yoke sustains that of the lever, B,the latter lever being supported by the stirrup or the pivot, l),resting in the bearing, Z, of the said stirrup. Also, that while all thepivots and bearings are in one vertical line, t-he yoke can play or movefreely both up and down as well as laterally, as it may without frictionagainst the stirrup.

By means of the yoke, the stirrup, the pivots, and dished or concavebearings applied and arranged together and with reference to the levers,A, B, and the rod, I, as described, I am able to obtain an advan tageousmethod of supporting the multiplying levers from the rod of thesteelyard, such not only enabling' the levers to oscillate freely, butto transmit their power or pressure correctly to the steelyard duringany of their oscillating movements.

Upon the steelyard rod, I, and over the upper crossbar of the yoke, Iplace a cap or bonnet, a2, to suitably cover or extend over the yoke andprotect the pivotl bearing from either dust or water.

IVliat, therefore, I claim as my invention or improvement isl. Thearrangement and application of the yoke stirrup, their concave steps orbearings and the pivots of the two multiplying and transmitting leverssubstantially as specified, the whole being for the purpose and tooperate as described.

2. I also claim combining with the rod, I, and the yoke applied theretoas described, the cap or bonnet, a2, the saine being for the purpose asspecified.

THADDEUS FAIRBANKS.

Iitnesses B. I-I. EDDY, F. P. HALE, Jr.

